[Pw_forum] problems on LiF bandstructure

[Giovanni Cantele]

Maybe a look to your output files might be helpful. If you do so, you discover that, for example, there are eigenvalues like
k =-1.0000 0.5000 0.0000 (  1856 PWs)   bands (ev):

   -21.6634  -3.3025  -3.3025  -2.3663  16.2882  16.2882  18.5338  20.1608


So, if the lowest band is around -21 eV and you fix the limit to -20, the DOS calculation will never catch that state. As a general rule, if you need the whole DOS
and not the DOS in a given interval, just get rid of the Emin and Emax parameters in the dos.x input, and dos.x will make all the job for you!!!!!! Alternatively, it is always a good practice
to look at all the output files, to understand what is going on.

Giovanni




> On 01 Dec 2015, at 16:35, evan <ewan26 at 126.com> wrote:
> 
> Hi, Paolo
> 
> I increased the energy range from -20 to 25 eV for integrating the DOS, but the result does not change, it is still 6 electrons below Fermi energy in my system.
> 
> For LDA calculation, with occupations = 'tetrahedra' defined in the nscf mode, the integerated  DOS is also 6 electrons. I do not know what is wrong in my calculations.
> 
> Regards.
> 
> Evan
> 
> 
> 
> 
> 
> 
> 
> At 2015-12-01 22:27:02, "Paolo Giannozzi" <p.giannozzi at gmail.com> wrote:
> 
> 
> On Tue, Dec 1, 2015 at 2:43 PM, evan <ewan26 at 126.com> wrote: 
> [...]  I calculated the dos of bulk LiF, but the results seem to be strange to me, as the integrated dos to Fermi energy (shifted to 0 eV, see attachments) is 6 electrons, actually there 8 electrons in the primitive unit cell of LiF. Can you tell me why?
> 
> 
> because your energy window for DOS calculation does not include the low-lying s states of F?
> 
> Paolo
> -- 
> Paolo Giannozzi, Dept. Chemistry&Physics&Environment,
> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
> 
> 
>  
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-- 

Giovanni Cantele, PhD
CNR-SPIN
c/o Dipartimento di Fisica
Universita' di Napoli "Federico II"
Complesso Universitario M. S. Angelo - Ed. 6
Via Cintia, I-80126, Napoli, Italy
e-mail: giovanni.cantele at spin.cnr.it
Phone: +39 081 676910
Skype contact: giocan74

ResearcherID: http://www.researcherid.com/rid/A-1951-2009
Web page: http://people.na.infn.it/~cantele